Where's the fluoride? Not in the water.

Though almost everyone agrees the compound prevents tooth decay, area water companies don't add it to their systems.

The American Dental Association endorses it. The American Medical Association endorses it. The Centers for Disease Control and the U.S. Public Health Service back it.

The practice itself began in some parts of this country in 1945, and studies in those pioneering areas found people benefited. But today, 56 years later, Central and Upper Bucks and Eastern Montgomery counties still don't have fluoridated public water.

Many area water departments, including Philadelphia Suburban, which serves more than 90 municipalities in five counties, do not add fluoride to the water they provide residents, and officials from those companies said they knew of no other in the area that did, except for the city's system.

According to recommendations from the CDC on fluoridation systems, "Data have consistently indicated that fluoridation is safe and is the most cost-effective and practical means for reducing the incidence of dental caries (tooth decay) in a community."

But not everyone is sold on adding fluoride to public water systems. For some, the idea of mass-medicating the populace is philosophically untenable. Others point to potential problems from fluoride consumption.

Although the fluoride ion is a naturally occurring trace element, people who ingest too much of it can develop mottled teeth or a disease similar to osteoporosis, according to the American Water Works Association. Despite this, the AWWA also endorsed fluoridation, though a little behind the government agencies, in 1976.

"We definitely support the use of fluoride; there have been clearly shown benefits to the use of fluoride," said Brian Funkhouser, chair of the Pennsylvania chapter of the AWWA. "If it is not handled correctly, there are certain risks involved. But we have no concerns over the use of it."

Tom Bradbury, in charge of regulatory affairs for the North Wales Water Authority, said there are some significant problems to be considered, however. He said fluoride levels are supposed to be kept between 0.7 and 1.2 milligrams per liter, a very small number, making it hard to accomplish. On the other hand, Bradbury said even at such low levels some people can't tolerate any fluoride, such as those with immune deficiencies or chemotherapy patients.

"There are a couple schools of thought: It is the best thing that has ever happened to humanity, or, it is a hazardous thing and it shouldn't be allowed," he said. "A lot of (the argument) is rhetoric coming from both sides, and unfortunately water providers are caught in the middle."

Some water providers have decided, largely for that very reason, to refuse to take a stand. They say they'll add fluoride when the people they serve demand it. The only problem with this theory is that everyone, and every municipality, on a system will have to agree, since public water systems are interconnected.

Philadelphia Suburban, which serves most of Eastern Montgomery County, has decided it will follow the will of the people, but that means getting consumers from Berks, Chester, Delaware, Montgomery and Bucks counties to agree.

"It is really a public policy, public health decision that is made outside of the water company," said Donna Alston, spokeswoman for Philadelphia Suburban.

Some of the other public water systems might have more luck getting agreement; several that don't use fluoride only serve a borough or other small area, such as the Perkasie or Doylestown authorities.

But even among only a relatively few people, the debate can be divisive. The topic can generate so much controversy, in fact, that the professors at Temple University's dental school won't talk to the press about it.